Machines for annealing the welded seams of longitudinally welded tubes



Aug. 9, 1966 D. GRUBE ETAL 3,265,378

MACHINES FOR ANNEALING THE WELDED SEAMS OF LONGITUDINALLY WELDED TUBESFiled Dec. 29, 1964 5 SheetsSneet 1 Fig. 1

Aug. 9, 1966 GRUBE A 3265.378

. MACHINES FOR ANNEALING THE WELDED SEAMS OF LONGITUDINALLY WELDED TUBESFiled Dec. 29, 1-964 5 Sheets-Sneet 2 Fig. .2

INALLY Aug. 9, 1966 D. GR UBE ETAL MACHINES FOR ANNEALING THE WELDEDSEAMS OF LONGITUD WELDED TUBES 5 Sheets-Sheet 5 Filed Dec. 29, 1964United States Patent v Dietrich Grube, Ratingen-Tiefeubroich, KarlWarnlre,

Dusseldorf-Reisholz, and Franz Sommerfeld, Neuss, Germany, assignors toSchloemann Aktiengesellschaft, Dusseldorf, Germany Filed Dec. 29, 1964,Ser. No. 421,829 Claims priority, applicaiogoGermany, Feb. 25, 1964,

8 Claims. (Cl. 266-) This invention relates to a welded-seam annealingmachine for longitudinally welded tubes. The annealing device hereemployed consists in general of .a number of inductors secured in aframe. For the equalisation of the welded joint the tube is guided alongat a definite speed and at a definite distance beneath the inductors. Toenable the requisite distance of the inductors from the welded seam tobe accurately maintained, the fastening frame has hitherto been providedwith vertically adjustable wheels, bearing upon and rolling upon thetube. According to the adjustment of the height of the wheels withrespect to the attachment frame the distance between the inductors andthe tube is made greater or less.

This known arrangement and construction of the annealing device has thedisadvantage that it is carried by the tube moving along beneath it, andtherefore the running wheels, owing to excessive heating from running onthe tube, have to be continuously cooled. As a result, not only is theannealing effect impaired, but the current induced by the inductors isalso affected by the wheels rolling on the tube. Finally, by thecarriage-like fastening frame, inspection of the inductors is hindered,and control of the distance between the inductors and the welded seam isrendered diflicult.

The object of the invention is to provide a machine for annealing weldedseams in pipes, wherein the welding device, instead of being carried bythe pipe guided along beneath it, is carried by the housing of thewelded-seam annealing device itself, and wherein the distance of theinductors from the pipe weld can be established by simple controllingmeans.

According to the invention this result is attained by the feature thatthe inductors that give rise to the annealing action are secured inaframe suspended from a system of swinging levers, the lever system beingin operative connection with one or more double-acting pressure pistons,the position of which in the cylinder can be regulated in dependenceupon the distance of the annealing device from the welded seam of thetube.

The regulating of the supply of pressure fluid to the pressure piston orpistons may advantageously be effected by means of a control valve thatcan be influenced by a key.

An important simplification of the controlling device is yielded if thecontrol valve, with the key, forms a common structural member soarranged on the frame of the annealing device as to be adjustable inheight. By this vertically adjustable arrangement of the control valveforming with the key a common structural member, any desired distance ofthe inductors from the Welded seam of the tube is adjustable in a simplemanner. In order that the key of the control valve may not itself comeinto contact with the tube, it co-operates with a roller pivotallyconnected with the frame of the annealing device and running upon thelongitudinally welded seam of the tube, in such a way that a tablesecured to the shaft of the roller or to its pivotal connection with theframe forms the operative surface thereof. This table may advanice tageously co-operate simultaneously with a disconnecting switch for theinductors, as soon as the distance thereof from the tube weld fallsbelow a minimum value.

In a further development of the invention, the lever system forming thesuspension for the annealing device consists of two levers coupledtogether and fulcrumed in a frame the height of which is adjustable, oneof these levers being coupled to a piston which can be supplied withfluid under pressure on both sides, and the pressure cylinder of whichis secured to the frame adjustable in height. This particularly simpleconstruction of the suspension has the special advantage that theposition of the pressure piston in the cylinder forms directly a measureof the distance of the inductors from the tube weld. In order that itmay be possible to adjust the annealing device parallel to the tubeweld, the fulcrum of one of the levers is so arranged in the frame as tobe adjustable in height.

One embodiment of a welded-tube annealing machine according to theinvention is illustrated by way of example in the accompanying drawings,in which:

FIGURE 1 shows a side view of the machine;

FIGURE 2 shows a front view looking in the direction of the arrow A inFIGURE 1;

FIGURE 3 is a circuit diagram of the invention; and

FIGURES 3a and 3b show on a larger scale a control valve in its lowerand upper controlling positions respectively.

The three inductors denoted by.1 are secured in .a frame formed fromgirders 2 and 3. On the girders 3 are arranged bearing blocks 4 forholding members 5, the upper ends 6 of which are pivotally connectedwith levers 7 and 8. These two levers 7 and 8 are pivotally coupledtogether by a rod 9. The lever 8 is pivotally mounted on a bearing block11, secured upon the girders 10. The lever 7 is pivotally mounted upon alever 12. The lever 12 is supported by a bearing block 13 secured uponthe girders 10. The position of the lever 12 is fixed by a rod 14 ofvariable length, one end of which is pivotally connected with a block:15, likewise secured upon the girders 10. According to the position ofa turn-buckle 16, the length of the rod 14 is decreased or increased,and the axis of oscillation 17 of the lever 7 is thereby shifted upwardsor downwards, so that the inductors .1 can be adjusted exactly parallelto the welded tube 18.

One arm 19 of the lever 8 is pivotally connected with the piston rod 20of a pressure cylinder 22, pivotally mounted on a frame member 21. Theheight of the inductors 1 is thereby directly determined by the positionof the piston rod 20. The position of the piston rod 20 is dependentupon the supply of pressure fluid to a pressure piston 47 (FIGURE 3)located in the double-acting cylinder 22. The controlling of the supplyof pressure fluid to the pressure piston 47 is effected by a controlvalve 23, which is arranged on a guiding block 36, and the height ofwhich is adjustable by means of a handwheel 24. The guiding block 33 issecured to connecting struts 34, which connect the girders 2 and 3 withone another. In FIGURE 3 the strut 34 is integral with the girder 2. l

By pressure pipes 25 and 26, which are arranged between the controlvalve 23 and upper and lower pressure-cylinder spaces, the pressurepiston 47 is supplied with pressure fluid above or below according tothe position of the control valve 23. With the control valve 23 in theposition shown in FIGURE 3, the pressure piston 47 is not being suppliedwith fluid on either side, so that its position remains constant. Theposition of the control valve 23 is affected from outside by a key orvalve rod 27, the operative face of which is formed by a table 28, whichis connected, by way of a joint member 48, with a roller 29 bearing onthe tube 18. The

roller 29 is connected by joint members 30 and 31 with a frame member32, which forms, with the girders 2, a fixed structural unit. If, owingto inaccuracies in the diameter of the tube for instance, the distance abetween the upper edge of the tube, or in other words the longitudinalweld of the tube, and the inductors 1, becomes greater, the table 28, inoperative connection with the roller 29, sink-s by the same amount.Since the key or valve rod 27 forms a rigid structural unit with the twocontrol pistons 49 and 50 of the valve 23, and the control piston 50 issubjected to pressure by a spring 51, this key 27 always remains incontact with the table 28, and therefore likewise descends with it. Thusthe control pistons 49 and 50 are at the same time displaced downwards(FIG- URE 3a), so that the middle space 54 of the control valve suppliedwith pressure fluid by a pump 52 by way of a pressure pipe 53, is incommunication with an annular groove 55, and thus, by way of theconnecting pipe 26, the lower cylinder space 56 of the cylinder 22 issupplied with pressure fluid. Since, moreover, with a lower position ofthe control pistons 49 and 50 of the control valve 23, an annular groove58 in the cylinder 23 is in open communication with the upper space 59of the control valve 23, the pressure fluid from the upper cylinderspace 57 of the cylinder 22 can flow freely back, by way of theconnecting pipe 25 and the annular groove 58, into the upper space 59 ofthe control valve 23, and from there, by way of a pipe 60, into a tank61, which is at atmospheric pressure, and which at the same time servesas a sump or storage vessel for the pump 52, so that the pressure piston47, owing to the supply of pressure below it, moves upwards, and thusmoves the levers 7 and 8, by

way of the piston rod 20, in the direction for a downward movement ofthe frame members 2 and 3. By this downward movement of the framemembers 2 and 3, to which, besides the inductors 1, the control valve 23is also secured, the key 27 acts in the opposite direction, that is, inthe closing direction, upon the control pistons 49 and 50 of the controlvalve. As soon as the distance a between the tube weld and the inductors1 is reached again, the control pistons 49 and 50 close the connectionbe tween the spaces 54 and 59 and the annular grooves 55 and 58respectively. The connecting pipes to the lower and upper cylinderspaces 56 and 57 are thus closed again, and the regulating ends.

If the distance a of the tube 18 from the inductors 1 diminishes, thekey 27, owing to a corresponding change of distance of the table 28,actuates the control valve 23 in such a manner that the control pistons49 and 50 move upwards, and thereby establish (FIGURE 3b) a connectionof the central pressure space 54 with the annular groove 58, and of thelower space 62 of the valve 23, which is in open communication by way ofthe connecting pipe 60 with the tank 61, with the annular groove 55. Inthis position of the control valve 23, the upper space 57 of thecylinder 22, is supplied with pressure fluid by way of the connectingpipe 25, whilst the lower cylinder space 56 is at atmospheric pressureby way of the connecting pipe 26, the annular groove 55, the lower space62 of the control valve 23, and the pipe 60, so that the pressure fluidlocated in this cylinder space can flow back into the tank 61. Thepressure piston 47, and the piston rod 20 connected with it, thereforeexecute a downward movement, whilst the lever system 7, 8 brings aboutan upward movement of the frame members 2 and 3, with the inductors 1.Since the control valve 23 is thus likewise raised with them, theannular grooves 55 and 58 and the control pistons 49 and 50 executerelatively to one another a closing movement. As soon as their closedposition, determined by the distance a, is reached, the connecting pipes25 and 26 to the cylinder spaces 56 and 57 are shut off, and theregulating operation is interrupted, until the distance a between thetube 18 and the inductors 1 changes again. In the closed position of thecontrol valve 23, the pressure liquid delivered by the pump 52 flowsback into the tank 61 by way of the pipe 53 and a non-return valve 65.

If a distance different from the distance a is to be maintained betweenthe tube 18 and the inductors 1, this is obtained by appropriatelyadjusting the height of the control valve 23 by means of the hand-wheel24. By shifting the control valve 23 downwards by rotating thehand-Wheel 24, the distance a is increased, and by shifting it upwardsthe distance is diminshed. The distance can be read off by means of apointer 63 on a scale 64 attached to the guiding block 33.

On the guiding block 33 .is at the same time provided a disconnectingswitch 35 for the inductors 1, the tripping pin 36 of which likewiseco-operates with the table 28. As soon as the inductors 1 sink below theminimum permissible distance a, the switch 35 comes into operation andinterrupts the supply of current.

' In order that any contact of the inductors 1 with the tube 18 may beprevented, wheels 66 maintaining the required distance are by way ofprecaution mounted in the frame member 32.

The girders 10 carrying the lever system are provided at both ends withguide rails 37, and their height, relative to a base structure 41 can beadjusted by means of a positioning drive 38, 39, 40. The lever systemthereby admits of being adjusted, jointly with the frame members 2' 3,and 34, and with the connecting stays 42, to tubes of any desireddimension.

A pointer 43 indicates upon a scale 44 the existing height of thecarrying frame for the lever system formed by the guiding bars 37. Theguiding bars 37 are guided on guide columns 45.

The tube 18, guided along underneath the inductors, is supported by aguide casing 46.

We claim:

1. A machine for annealing welded seams in longitudinally welded tubes,comprising: a base structure, means carried by the base structure forsupporting a welded pipe to be annealed, a system of swinging leverspivotally carried by the base structure, a frame suspended from theswinging levers at a selected height above the tube weld to be annealed,an annealing device carried by the said frame, at least onedouble-acting piston-and-cylinder unit, means operatively connecting apiston of the piston-andcylinder unit with the system of swinginglevers, means for selectively supplying fluid under pressure to thecylinder spaces of the piston-and-cylinder uni-t, and therebycontrolling the height of the annealing device above the tube weld to beannealed, and means for regulating the supply of pressure fluid to thepiston-an-d-cylinder unit in dependence upon the distance of theannealing device from the welded seam of the tube.

2. A machine for annealing welded seams as claimed in claim 1, the saidmeans for regulating the supply of pressure fl-uid comprising: a controlvalve, and a key for influencing the control valve.

3. A machine for annealing welded seams as claimed in claim 2, thecontrol valve being mounted on the frame carried by the swinging levers.

4. A machine for annealing welded seams as claimed in claim 2, furthercomprising: a table secured to the key of the control valve, and aroller pivotally mounted on the frame carried by the swinging levers soas to roll upon the Welded tube seam, and to co-operate with the saidtable in regulating the supp-1y of pressure fluid.

5. A machine for annealing welded seams as claimed in claim -1,comprising means for supplying heating means to the annealing device,and means for automatically disconnecting this supply of heating meanswhenever the distance between the annealing means and the tube fallsbelow a predetermined minimum permissible distance.

6. A machine for annealing welded seams as claimed in claim 1, furthercomprising: a girder \frame so mounted on the base structure as to beadjustable up and down relatively thereto, the system of swinging leversconsisting of two levers coupled together, and each pivotally mounted onthe said adjustable girder frame, and the pressure cylinder thatcontains the double-acting piston coupled to one of the swinging leversalso being attached to the said girder frame.

7. A maohine for annealing welded sea-ms as claimed in claim 1, furthercomprising means for varying the height of the fulcrum of one of theswinging levers relatively to the base structure.

8. A machine for annealing welded seams as claimed in claim 6, furthercomprising means for varying the height, relative to the girder frame,of the fulcrum of the swinging lever which is not directly coupled tothe double-acting piston.

References Cited by the Examiner UNITED STATES PATENTS 1/1952 Body219-8.5

JOHN F. CAMPBELL, Primary Examiner.

WHITMORE A. WILTZ, M. L. FAIGUS, Examiners.

1. A MACHINE FOR ANNEALING WELDED SEAMS IN LONGITUDINALLY WELDED TUBES,COMPRISING: A BASE STRUCTURE, MEANS CARRIED BY THE BASE STRUCTURE FORSUPPORTING A WELDED PIPE TO BE ANNEALED, A SYSTEM FOR SWINGING LEVERSPIVOTALLY CARRIED BY THE BASE STRUCTURE, A FRAME SUSPENDED FROM THESWINGING LEVERS AT A SELECTED HEIGHT ABOVE THE TUBE WELD TO BE ANNEALED,AN ANNEALING DEVICE CARRIED BY THE SAID FRAME, AT LEAST ONEDOUBLE-ACTING PISTON-AND-CYLINDER UNIT, MEANS OPERATIVELY CONNECTING APISTON OF THE PISTON-ANDCYLINDER UNIT WITH THE SYSTEM OF SWINGINGLEVERS, MEANS FOR SELECTIVELY SUPPLYING FLUID UNDER PRESSURE TO THECYLINDER SPACES OF THE PISTON-AND-CYLINDER UNIT, AND THEREBY CONTROLLINGTHE HEIGHT OF THE ANNEALING DEVICE ABOVE THE TUBE WELD TO BE ANNEALED,AND MEANS FOR REGULATING THE SUPPLY OF PRESSURE FLUID TO THEPISTON-AND-CYLINDER UNIT IN DEPENDENCE UPON THE DISTANCE OF THEANNEALING DEVICE FROM THE WELDED SEAM OF THE TUBE.